Yes, you need to enter both tests on his profile. But first you need to change the privacy level of the person tested from 'private' to 'private with a public family tree' so that the DNA information displays for others to see. On his profile, click on the 'privacy' tab. Click on the small button next to the new privacy level, and then click 'set new privacy level'. Now you're ready to add information about his second DNA test. At the top right of his profile you'll see 5 entries with drop-down lists (my wikitree, his wiki id, add, find, help). 'Hover' on his wiki id (his surname-#), and from the drop-down list, choose DNA. On that page select the 'DNA tests' tab. Scroll down until you find 'Add a new test'. Enter the information about his Family Finder test there.